A limit result for a system of particles in random environment

We consider an infinite system of particles in one dimension, each particle performs independant Sinai's random walk in random environment. Considering an instant $t$, large enough, we prove a result in probability showing that the particles are trapped in the neighborhood of well defined points of the lattice depending on the random environment the time $t$ and the starting point of the particles.Comment: 11 page

Convergence of nonlocal threshold dynamics approximations to front propagation

In this note we prove that appropriately scaled threshold dynamics-type algorithms corresponding to the fractional Laplacian of order $\alpha \in (0,2)$ converge to moving fronts. When $\alpha \geqq 1$ the resulting interface moves by weighted mean curvature, while for $\alpha <1$ the normal velocity is nonlocal of ``fractional-type.'' The results easily extend to general nonlocal anisotropic threshold dynamics schemes.Comment: 19 page

Non-equilibrium phase transitions in one-dimensional kinetic Ising models

A family of nonequilibrium kinetic Ising models, introduced earlier, evolving under the competing effect of spin flips at {\it zero temperature} and nearest neighbour random spin exchanges is further investigated here. By increasing the range of spin exchanges and/or their strength the nature of the phase transition 'Ising-to-active' becomes of (dynamic) mean-field type and a first order tricitical point is located at the Glauber ($\delta=0$) limit. Corrections to mean-field theory are evaluated up to sixth order in a cluster approximation and found to give good results concerning the phase boundary and the critical exponent $\beta$ of the order parameter which is obtained as $\beta\simeq1.0$.Comment: 15 pages, revtex file, figures available at request from [email protected] in postscript format, submitted to J.Phys.

Anomalous tag diffusion in the asymmetric exclusion model with particles of arbitrary sizes

Anomalous behavior of correlation functions of tagged particles are studied in generalizations of the one dimensional asymmetric exclusion problem. In these generalized models the range of the hard-core interactions are changed and the restriction of relative ordering of the particles is partially brocken. The models probing these effects are those of biased diffusion of particles having size S=0,1,2,..., or an effective negative "size" S=-1,-2,..., in units of lattice space. Our numerical simulations show that irrespective of the range of the hard-core potential, as long some relative ordering of particles are kept, we find suitable sliding-tag correlation functions whose fluctuations growth with time anomalously slow ($t^{{1/3}}$), when compared with the normal diffusive behavior ($t^{{1/2}}$). These results indicate that the critical behavior of these stochastic models are in the Kardar-Parisi-Zhang (KPZ) universality class. Moreover a previous Bethe-ansatz calculation of the dynamical critical exponent $z$, for size $S \geq 0$ particles is extended to the case $S<0$ and the KPZ result $z=3/2$ is predicted for all values of $S \in {Z}$.Comment: 4 pages, 3 figure

Non equilibrium steady states: fluctuations and large deviations of the density and of the current

These lecture notes give a short review of methods such as the matrix ansatz, the additivity principle or the macroscopic fluctuation theory, developed recently in the theory of non-equilibrium phenomena. They show how these methods allow to calculate the fluctuations and large deviations of the density and of the current in non-equilibrium steady states of systems like exclusion processes. The properties of these fluctuations and large deviation functions in non-equilibrium steady states (for example non-Gaussian fluctuations of density or non-convexity of the large deviation function which generalizes the notion of free energy) are compared with those of systems at equilibrium.Comment: 35 pages, 9 figure

Calibration of the Particle Density in Cellular-Automaton Models for Traffic Flow

We introduce density dependence of the cell size in cellular-automaton models for traffic flow, which allows a more precise correspondence between real-world phenomena and what observed in simulation. Also, we give an explicit calibration of the particle density particularly for the asymmetric simple exclusion process with some update rules. We thus find that the present method is valid in that it reproduces a realistic flow-density diagram.Comment: 2 pages, 2 figure

Debating the European Union: dynamics of argumentation in political debates

This thesis is a discursive investigation of contested political discourse. Using Discursive Psychology, I analyse broadcast political debates on the European Union to explore how politicians advocate and defend their political positions in an argumentative context of justification and criticism. Past research in social psychology and cognate disciplines has investigated ideology from a multitude of views. Following a move away from mainstream approaches I demonstrate how some qualitative approaches treat it as a live matter in broadcast political debates. For my data I have chosen the controversial political battleground that is the European Union and what it means for Britain. The contribution of Discursive Psychology comes in highlighting the contested, rhetorical, nature of ideology . In this thesis I draw upon Discursive Psychology to explore how this contestation unfolds as situated practice in multi-party conversations about the EU. Politicians will argue in favour or against the EU, often on the grounds of what the implication is for Britain. In this thesis I argue that Discursive Psychology is best equipped to allow us to study this as an activity; an observable, and contextual, social action. The analytical chapters focus on three interrelated aspects of political argumentation: the construction and use of factual claims (including demonstrations of knowledge statuses ) and counterclaims, the role of overlapping talk, and the function of laughter and derision. The first analytical chapter seeks to elucidate some of the ways in which facts and situated knowledge displays of them are oriented to as an argumentative matter and how they can be challenged. The second analytic chapter illustrates the role played by overlapping talk and challenges in managing the argument at hand. The last analytic chapter focuses on the accomplishment of derision in broadcast political debates, particularly on how derision can be used as form of counterclaim. Ultimately, this thesis demonstrates the usefulness of Discursive Psychology in understanding the discursive dynamics of mobilisation, contestation, and defence of contrasting viewpoints in the service of political argumentation. Discursive Psychology can help social psychologists get a much deeper appreciation of the situated, and discursively dynamic, nature of political argumentation and conflict in talk

Safety and on-treatment efficacy of telaprevir: the early access programme for patients with advanced hepatitis C

Background and aim Severe adverse events (AEs) compromise the outcome of direct antiviral agent-based treatment in patients with advanced liver fibrosis due to HCV infection. HEP3002 is an ongoing multinational programme to evaluate safety and efficacy of telaprevir (TVR) plus pegylated-interferon-alpha (PEG-IFN alpha) and ribavirin (RBV) in patients with advanced liver fibrosis caused by HCV genotype 1 (HCV-1).Methods 1782 patients with HCV-1 and bridging fibrosis or compensated cirrhosis were prospectively recruited from 16 countries worldwide, and treated with 12 weeks of TVR plus PEG-IFN/RBV, followed by 12 or 36 weeks of PEG-IFN and RBV (PR) alone dependent on virological response to treatment and previous response type.Results 1587 patients completed 12 weeks of triple therapy and 4 weeks of PR tail (53% cirrhosis, 22% HCV-1a). By week 12, HCV RNA was undetectable in 85% of naives, 88% of relapsers, 80% of partial responders and 72% of null responders. Overall, 931 patients (59%) developed grade 1-4 anaemia (grade 3/4 in 31%), 630 (40%) dose reduced RBV, 332 (21%) received erythropoietin and 157 (10%) were transfused. Age and female gender were the strongest predictors of anaemia. 64 patients (4%) developed a grade 3/4 rash. Discontinuation of TVR due to AEs was necessary in 193 patients (12%). Seven patients died (0.4%, six had cirrhosis).Conclusions in compensated patients with advanced fibrosis due to HCV-1, triple therapy with TVR led to satisfactory rates of safety, tolerability and on-treatment virological response with adequate managements of AEs.Janssen PharmaceuticsUniv Milan, Div Gastroenterol, Dept Med, Fdn IRCCS Ca Granda Osped Maggiore Policlin, Milan, ItalyHosp Univ 12 Octubre, Secc Aparato Digest, Madrid, SpainIM Sechenov First Moscow State Med Univ, EM Tareev Clin Nephrol Internal & Occupat Med, Moscow, RussiaUniversidade Federal de São Paulo, Viral Hepatitis Div Infect Dis, Outpatient Clin HIV, São Paulo, BrazilUniv Sydney, Royal Prince Alfred Hosp, AW Morrow Gastroenterol & Liver Ctr, Sydney, NSW 2006, AustraliaCharles Univ Prague, Fac Med 1, Dept Internal Med, Prague, Czech RepublicCent Mil Hosp Prague, Prague, Czech RepublicUniv Libre Brussels, Dept Gastroenterol Hepatopancreatol & Digest Onco, Erasme Univ Hosp, Liver Unit, Brussels, BelgiumCarol Davila Univ Med & Pharm, Natl Inst Infect Dis, Bucharest, RomaniaJanssen Pharmaceut, B-2340 Beerse, BelgiumJanssen Pharmaceut, Paris, FranceJanssen Res & Dev, Titusville, NJ USAJanssen Res & Dev, High Wycombe, Bucks, EnglandJanssen Cilag AG, Zug, SwitzerlandHannover Med Sch, D-30623 Hannover, GermanyUniversidade Federal de São Paulo, Viral Hepatitis Div Infect Dis, Outpatient Clin HIV, São Paulo, BrazilWeb of Scienc

Exact Tagged Particle Correlations in the Random Average Process

We study analytically the correlations between the positions of tagged particles in the random average process, an interacting particle system in one dimension. We show that in the steady state the mean squared auto-fluctuation of a tracer particle grows subdiffusively as $sigma^2(t) ~ t^{1/2}$ for large time t in the absence of external bias, but grows diffusively $sigma^2(t) ~ t$ in the presence of a nonzero bias. The prefactors of the subdiffusive and diffusive growths as well as the universal scaling function describing the crossover between them are computed exactly. We also compute $sigma_r^2(t)$, the mean squared fluctuation in the position difference of two tagged particles separated by a fixed tag shift r in the steady state and show that the external bias has a dramatic effect in the time dependence of $sigma_r^2(t)$. For fixed r, $sigma_r^2(t)$ increases monotonically with t in absence of bias but has a non-monotonic dependence on t in presence of bias. Similarities and differences with the simple exclusion process are also discussed.Comment: 10 pages, 2 figures, revte

Three decades of infant motor development:Cohort effects in motor skill onsets

Infant motor development is affected by the sociocultural context in which it takes place. Because societal and cultural practices are dynamic, this exploratory study examined whether the ages at which infants typically learned to crawl, cruise, and walk changed over the past 3 decades. We compiled archival data from 1,306 infants born between January 31, 1992, and December 10, 2021. Parents originally reported milestone onsets in interviews and by using diaries. For each motor milestone, a linear regression model predicted the onset age using birth date. Segmented regression analyses inspected changes in slopes over time. Covariates included rural/urban housing, gestation age, season of birth, and birth weight. Infants’ average crawling, cruising, and walking onset ages changed over time. After controlling for the covariates, infants’ crawling onset age steadily increased until 2012, after which crawling onset age decreased. Infants’ cruising onset age increased from 1991 to 2001, after which cruising onset age remained stable. After controlling for the covariates, infants’ walking onset increased until 2015, after which walking onset age decreased. Thus, when infants were born explained a small but significant amount of variability in infant motor skill onset. While the current study showed that motor development changed over the years, motor development is just a model system for development more generally: Cohort effects may be pervasive across developmental domains. Using motor development as a model system for studying change suggests that generational effects due to a changing society may be pervasive across developmental domains